iOS心率检测算法

iOS心率检测算法是一种用于通过iPhone或iPad等iOS设备测量用户心率的算法。通过使用设备上的内置传感器，该算法能够准确地检测和记录用户的心率数据。本文将介绍iOS心率检测算法的原理和应用，并提供一个案例代码以帮助读者更好地理解和应用该算法。

swift
import UIKit
import HealthKit
class HeartRateViewController: UIViewController {
    let healthStore = HKHealthStore()
    override func viewDidLoad() {
        super.viewDidLoad()
        checkAuthorization()
    }
    func checkAuthorization() {
        guard HKHealthStore.isHealthDataAvailable() else {
            // 设备不支持健康数据
            return
        }
        let heartRateType = HKObjectType.quantityType(forIdentifier: .heartRate)!
        let typesToShare: Set = []
        let typesToRead: Set = [heartRateType]
        healthStore.requestAuthorization(toShare: typesToShare, read: typesToRead) { (success, error) in
            if success {
                self.startHeartRateQuery()
            } else {
                // 授权失败
            }
        }
    }
    func startHeartRateQuery() {
        let heartRateType = HKObjectType.quantityType(forIdentifier: .heartRate)!
        let query = HKObserverQuery(sampleType: heartRateType, predicate: nil) { (query, completionHandler, error) in
            self.fetchLatestHeartRateSample { (sample) in
                guard let sample = sample else {
                    return
                }
                // 处理心率数据
                let heartRate = sample.quantity.doubleValue(for: HKUnit.count().unitDivided(by: .minute()))
                print("Heart Rate: \(heartRate)")
            }
        }
        healthStore.execute(query)
    }
    func fetchLatestHeartRateSample(completion: @escaping (HKQuantitySample?) -> Void) {
        let heartRateType = HKObjectType.quantityType(forIdentifier: .heartRate)!
        let sortDescriptor = NSSortDescriptor(key: HKSampleSortIdentifierStartDate, ascending: false)
        let query = HKSampleQuery(sampleType: heartRateType, predicate: nil, limit: 1, sortDescriptors: [sortDescriptor]) { (query, samples, error) in
            guard let samples = samples as? [HKQuantitySample], let sample = samples.first else {
                completion(nil)
                return
            }
            completion(sample)
        }
        healthStore.execute(query)
    }
}